It's all a gimmick to get people riled up and excited - "MUST BUY NOW BEFORE IT'S GONE - it's not like you'll be able to find copies on Ebay or anything!" XD I just roll my eyes and move on.
Did anyone ever find that "Alvin's Dream Sequence" from the Christmas special seriously creepy? It made me nervous as a kid, and it still does. Like I (or Alvin) was drugged or something XD Almost as trippy as the Heffalumps and Woozles from Winnie the Poo.